This invention relates to a wear runner for an excavating bucket and, more particularly to a multipart runner which permits replacement of wearable surfaces.
The buckets to which the instant invention has advantageous application are dragline buckets which are normally equipped with welded on runner strips. These strips extend along the bottom wall longitudinally from the open front of the bucket to the closed rear. Exemplary of runners which have been used for many years are those seen in U.S. Pat. Nos. 2,492,905 and 2,723,471. These runners were employed to protect the bottom wall of the bucket against undue wear but necessitated considerable down-time when runner replacement was indicated. Other types of elements secured to bucket bottoms are those seen in U.S. Pat. Nos. 1,244,117 and 2,325,336.
The instant invention in providing replaceable runners makes use of a dovetail connection between a wearable element and a base element adapted to be generally permanently secured to the bucket bottom. Dovetail connections between a wearable part and a base part have been employed in excavating equipment previously. For example, a wear cap for one type of excavating tooth is seen in co-owned U.S. Pat. No. 2,896,345 and a wear cap for a second type of excavating tooth is seen in co-owned U.S. Pat. No. 3,082,555. In recent years, however, the dovetail connection for wear caps has been discontinued for newer tooth designs as seen in co-owned U.S. Pat. Nos. 4,317,300 and 4,326,348.
The inventive dovetail connection differs from those employed previously in connection with tooth wear caps in having the dovetail surfaces diverge so that the wearable element in the process of installation not only becomes more tightly affixed to the base element but also moves upwardly and into closer contact therewith.
Other objects and advantages of the invention may be seen in the details of construction and operation set down in the ensuing specification.